1. Field of the Invention
The present invention relates to apparatuses for cutting, and more particularly to apparatuses for cutting vegetation such as tree branches, trees, and brush.
2. Description of the Invention Background
Various apparatuses which are useful for cutting vegetation such as brush or tree branches are known in the prior art. For example, U.S. Pat. No. 4,769,977 to Milbourn discloses a brush cutter which includes a backhoe, an articulated boom structure formed by three booms which is carried by the backhoe, a workhead attached to the outer boom, and a rotary cutter carried by the workhead. A hydraulic motor drives the rotary cutter, and the booms are movable through hydraulic pistons and cylinders. The backhoe is commercially available with a single engine providing power to drive the backhoe and the hydraulic system for operating two of the booms. According to that patent, the hydraulic system also operates the third boom and the hydraulic motor.
U.S. Pat. No. 4,509,315 to Giguere discloses a mowing apparatus to cut various kinds of vegetation, which includes a floating work head carried by an articulated hydraulic arm which is attached to a work vehicle. The work head carries a rotating element having a pair of cutting blades thereon, and an undescribed motor which rotates the rotating element. Also, U.S. Pat. No. 4,502,269 to Cartner discloses a boom mower which includes a tractor having an engine, a boom assembly connected at one end to the tractor, and a mowing apparatus connected to the other end of the boom assembly. The mowing apparatus includes a cutter assembly and a hydraulic motor powered by a pump driven by the engine for rotating the cutter assembly, and a boom articulation control means is disclosed which includes hydraulic pistons and cylinders.
Each of the above references has the disadvantage that a separate power supply is not disclosed for supplying power solely to the cutting assembly thereof. For example, in the Milbourn patent, a standard backhoe hydraulic system powered by a single engine which normally powers two booms is modified to supply hydraulic power both to an additional boom and a cutting assembly. Such a modification can place much greater requirements on the backhoe engine, even requirements above the capability of the single engine, which can result in less than a predetermined amount of power being supplied to the cutting assembly.
U.S. Pat. No. 3,061,996 to Ripps discloses a mower which includes a separate engine which provides power to operate a cutter bar. The mower includes a tractor, a boom mounted on the tractor, a platform mounted to the boom to which the engine and the cutter bar are mounted, hydraulic cylinders to move the boom and the platform, and pressure means of the tractor for supplying fluid under pressure to the cylinders. The Ripps patent has the disadvantage, however, that the separate engine is located at the end of the boom away from the tractor so that the engine can be directly mechanically connected to the cutter bar. Such an arrangement can add unnecessary weight to the end of the boom, which can adversely affect the speed at which the boom can be moved and the overall balance of the apparatus, as well as posing a greater danger that the boom or the hydraulic cylinders will break.